I need to weld in a chunk of .25" aluminum to repair the skeg on my outdrive. The skeg and lower unit are one piece of cast aluminum. It's an older OMC. I will weld it with a MIG. The remaining piece of the skeg is a little bent and I need to straighten or cut the rest off. I would much rather straighten it though. Can I heat it up and hammer it back?
My money says you'll have no success by heating, but you are likely to do some damage by distorting the entire housing. Don't know if aluminum is hot short, but if it is, heating would make breaking easier, not harder. Maybe someone that repairs outdrives will chime in.
Harold
IIRC, Aluminum becomes more mallable cold like at dry ice temp. Do you have a sample to test?
I used to be in the prop repair business a while back, and along with prop repair, skeg and cavitation plate replacement was pretty common practice as well. I assume you have the replacement skeg already...........since your stub of the original skeg is bent, it is best to lay a flat edge along the housing (torpedo) and scribe a staight line to what ever height is needed to eliminate the bend and cut or grind off that section. Replacement skegs are long enough so that the old skeg can be remnoved completely to the lower housing and rewelded......
Whatever you do do not heat it up with the expectations of straighteng what is left or you more than likely will be replacing the entire lower housing.
Bevel the end of the replacement skeg and tack it in place on both sides at both ends and the middle. Weld just a short length at a time. Its best to strip out the innerds in the lower unit, and you may find that you did get some warp or distortion, and its a lot eaiser to make it right with the innerds out than having them stuck inplace and not able to get the out without sacrificing the carrier assembly or lock rings...... Visit my website:
I would think long and hard before doing this. The outdrive will function quite happily without the skeg. Ken.
Yes but you will chew up props if you hit debris.
Agreed but......... The only time I chewed up a prop was the time I knocked my skeg off (rescue mission - long story). Haven't dinged it again. A stainless prop helps - in fact is manditory when cruising the waters of the north coast. The AL (pot metal?) props are useless - I had one fold up hitting a rotton 2 X 4. Regards. Ken (30 years on the water).
All the money I spent fixing my al prop over the years I probably could have bought a stainless. Too late now, I'm selling it and agreed to fix the skeg for the buyer.
I had a pro do mine. He did it cold, Two hits with a hammer with a large backing dolly (piece of railroad rail) got it straight. He's done this before! Charged me $25.
Aluminum props are best in rocky waters. Stainless props don't resist rocks much better than aluminum does, are 4X more expensive to replace or repair, and they're more likely to damage the engine when they hit something.
So why don't I just stay away from the rocks? Because rocks are everywhere on northern MN lakes like Vermillion. Rockpiles suddenly appear in what looks like mid-lake with the sonar saying 30 feet. It would take years to "learn" that lake (40,000 acres, 24 miles long,
313 miles of shorel>The AL (pot metal?) props are useless - I had one fold up hitting a rotton 2 >X 4.
Its a big misconception that SS props are bullet proff like a lot think.....They do get bent, and are much costlier to repair. I prefer alum props, even though I could buy any prop wholesale or fix my own, I still went with alum. Most work on lower units that got damaged used SS props, and while they ay not break, like a cast alum one will sometimes they impart quite a bit of shock to the lower unit parts. A lot of foks thik the rubber hub is there to slip if you hit something, its not, its there for a shock absorber for shifting between forward and reverse, and if it slips just a hair its inevitable its gonna continue slipping once its initial set is broke free..........
Early Merc props were cast alum, OMC Johnson and Evinrudes are mainly die cast and were always a problem welding up.........Volve were the best due to their alloy of aluminum they used.......Michigan wheel and Propco were the most forgiving in regards to welding and repair as they are all sandcast.........
The new rage now is composite props that have sockets or dovetails that each blade can be relaced indiividually by the owner if it gets damaged... Visit my website:
I wouldn't be afraid to run stainless on my omc. It has a shear pin right at the prop that protects it quite well. I've sheared it numerous times by hitting debris. I can replace the pin on the water easily. I've even sheared it by accidently shifting into reverse while moving forward.
"Harold & Susan Vordos"wrote: (clip) Don't know if aluminum is
^^^^^^^^^^^^^ Aluminum is hot short.
Thanks! I'll try to remember it this time.
Harold
Well...there's hot forging alloys... 4000-something for instance. I think it's a hypersil alloy. Used for pistons, con rods etc.
Tim
-- "I've got more trophies than Wayne Gretsky and the Pope combined!" - Homer Simpson Website @
I don;t know if they even make a prop shear pin type prop mount any more on any new motors.In years past most of the smaller OB had shear pins in the Johnson and evinrude and some others, but splined hub was used by the vast majority. While you may have had shear pins shear as designed, I have also seen hubs in these props tear out at the shear pin section as well.....so it goes both ways. Visit my website:
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